Question

what is the range of declinations for a circumpolar stars if you are located at 20 degrees south latitude? 70 to 90 degrees declination -20 to -90 degrees declination 20 to 90 degrees declination -70 to -90 degrees declination

Explanation:

Circumpolar stars are those that never set. At a latitude $\varphi$ in the Southern Hemisphere, the declination $\delta$ of circumpolar stars satisfies $\delta\leqslant-(90 - |\varphi|)$. Given a latitude of 20 degrees South ($\varphi=- 20^{\circ}$), then $90 - |\varphi|=90 - 20=70$. So the declination range of circumpolar stars is from - 70 to - 90 degrees.

Answer:

D. -70 to -90 degrees Declination